This disclosure relates to propulsion systems, and more particularly to a hybrid propulsion system.
Liquid systems and solid systems are the two basic types of rocket propulsion systems that are most widely used in the rocket industry. In a solid propellant system, solid rocket fuel and an oxidizer are mixed together and allowed to cure inside a rocket case to form a solid propellant material, which is then ignited in the rocket case. Upon ignition, pressure forms within the rocket case and gases are released through a nozzle to produce thrust. In a solid propellant system, the solid propellant burns uninterrupted until all the propellant is exhausted, which can be undesirable in certain circumstances.
In a liquid system, a liquid oxidizer is fed into a combustion chamber in combination with a liquid fuel. The oxidizer and liquid fuel are mixed in the combustion chamber, where they react to produce gases under high temperature and high pressure. The gases exhaust through a nozzle from the combustion chamber to thereby produce thrust. Although widely used, there are certain drawbacks associated with liquid propulsion systems.
Another type of rocket propulsion system is the hybrid system. A hybrid system combines aspects of both liquid systems and solid systems in that one propellant is stored as a solid and another propellant is stored as a liquid. In a typical system, the solid material is used as the fuel and the liquid material is used as the oxidizer. A variety of materials can be used as the solid fuel, including Plexiglas (polymethyl methacrylate (PMMA)), high density polyethylene (HDPE), hydroxyl terminated polybutadiene (HTPB), etc. Nitrous Oxide is a commonly used as the oxidizer, although other oxidizers can be used.